Ce-mag.com is the world's foremost on-line resource for international
developments in regulatory compliance for electronics engineers.

In the latest issue BPL, PLC and PLT covered in very great detail from
the regulatory stand point.

http://www.ce-mag.com/archive/03/ARG/hansen1.html

http://www.ce-mag.com/archive/03/ARG/hansen2.html

Brief excerpt (Conclusion)
"PLC technology, in principle, is potentially attractive, if it were
to become compatible with existing telecom technologies. PLC
technology is still premature in terms of EMI prevention. PLC has
little to offer over the competitors and certainly does not justify
more EMI.

Standards will evolve relatively slowly. The requirement of the EMC
Directive with harmonized norms (to conducted EN 55022) are not met by
most PLC systems, regardless of the stricter limits of regulations
such as NB 30.

It is unlikely that PLC will experience widespread application under
its currently implemented status. With delays in implementation and
lackluster client acceptance, even the business case is becoming less
attractive."

The article is written from the European viewpoint but very relevant
to BPL.